Pets can be welcome members to a household, but often pet containers such as a pet kennel or house or litter box can become malodorous. In addition to taking on the animal's odor, such containers may shelter fleas and other parasites brought in by the animal. In the case of litter boxes, unless the litter material is replaced sufficiently frequently, animal waste can create not only an unpleasant odor but a potential health hazard as well.
Electric motor driven fan blades may be used to create an air flow to air out the animal house or little box, but such fans are noisy, and can present an danger to children from moving fan blades and AC voltage used to power the fan. Further, with respect to odors, a fan merely dissipates the odor into the nearby environment without addressing the cause of the odor, which may include germs and bacteria.
It is known to produce an air flow using electro-kinetic techniques, by which electrical power is directly converted into a flow of air without mechanically moving components. One such system is described in U.S. Pat. No. 4,789,801 to Lee (1988), depicted herein in simplified form as FIGS. 1A and 1B. Lee's system 10 includes an array of small area ("minisectional") electrodes 20 that is spaced-apart symmetrically from an array of larger area ("maxisectional") electrodes 30. The positive terminal of a pulse generator 40 that outputs a train of high voltage pulses (e.g., 0 to perhaps +5 KV) is coupled to the minisectional array, and the negative pulse generator terminal is coupled to the maxisectional array.
The high voltage pulses ionize the air between the arrays, and an air flow 50 from the minisectional array toward the maxisectional array results, without requiring any moving parts. Particulate matter 60 in the air is entrained within the airflow 50 and also moves towards the maxisectional electrodes 30. Much of the particulate matter is electrostatically attracted to the surface of the maxisectional electrode array, where it remains, thus conditioning the flow of air exiting system 10. Further, the high voltage field present between the electrode arrays can release ozone into the ambient environment, which appears to destroy or at least alter whatever is entrained in the airflow, including for example, bacteria.
In the embodiment of FIG. 1A, minisectional electrodes 20 are circular in cross-section, having a diameter of about 0.003" (0.08 mm), whereas the maxisectional electrodes 30 are substantially larger in area and define a "teardrop" shape in cross-section. The ratio of cross-sectional areas between the maxisectional and minisectional electrodes is not explicitly stated, but from Lee's figures appears to exceed 10:1. As shown in FIG. 1A herein, the bulbous front surfaces of the maxisectional electrodes face the minisectional electrodes, and the somewhat sharp trailing edges face the exit direction of the air flow. The "sharpened" trailing edges on the maxisectional electrodes apparently promote good electrostatic attachment of particular matter entrained in the airflow. Lee does not disclose how the teardrop shaped maxisectional electrodes are fabricated, but presumably they are produced using a relatively expensive mold-casting or an extrusion process.
In another embodiment shown herein as FIG. 1B, Lee's maxisectional sectional electrodes 30 are symmetrical and elongated in cross-section. The elongated trailing edges on the maxisectional electrodes provide increased area upon which particulate matter entrained in the airflow can attach. Lee states that precipitation efficiency and desired reduction of anion release into the environment can result from including a passive third array of electrodes 70. Understandably, increasing efficiency by adding a third array of electrodes will contribute to the cost of manufacturing and maintaining the resultant system.
Lee's electrostatic techniques offer advantage over conventional electric fans, but Lee's maxisectional electrodes are relatively expensive to fabricate. It is also difficult to increase efficiency in a Lee-type system without including a third array of electrodes.
Thus, there is a need for an electro-kinetic air transporter-conditioner that can be produced in a format suitable for deodorizing, conditioning, and ionizing the area within an animal house and/or a litter box. Such a device should provide improved efficiency over Lee-type systems, without requiring expensive production techniques to fabricate the electrodes. Preferably such a conditioner should function efficiently without requiring a third array of electrodes. Further, such a device should optionally generate safe amounts of ozone, for example to remove odor from ambient air. Preferably such a device should be manufacturable in a portable size, for example for use within a closed closet.
The present invention provides a method and apparatus for electro-kinetically transporting and conditioning air. Device embodiments are described to provide a flow of air that can contain ions and safe amounts of ozone, to deodorize and otherwise condition the air in the environment of an animal house and/or litter box. Further, such devices may be battery operated, to promote safety and portability.